In order to reduce the marketing costs of merchants promoting products over multiple rounds on social networks,this study made a exploration on the selection of boosting nodes during the process of multi-round influence propagation. Based on the model of multi-round influence boosting propagation mode, an adaptive strategy for choosing boosting nodes was designed. Given known seed nodes, this strategy could find an efficient method to minimize the number of marketing rounds needed to reach a certain threshold of social influence, with nearly linear algorithmic complexity. Experimental results show that compared to existing heuristic algorithms and non-adaptive algorithms, the designed adaptive strategy can reduce the promotion rounds required to reach a specified threshold by 7.3%~18.3%, effectively reducing the promotion cost.